[PATCH v3 11/13] fdt: video: omap: add framebuffer and panel bindings

Dario Binacchi dariobin at libero.it
Sat Feb 22 14:05:47 CET 2020


Add device-tree binding documentation for ti framebuffer and generic
panel output driver.

Signed-off-by: Dario Binacchi <dariobin at libero.it>
Reviewed-by: Simon Glass <sjg at chromium.org>
---

Changes in v3: None
Changes in v2: None

 .../video/tilcdc/panel.txt                    | 66 +++++++++++++++
 .../video/tilcdc/tilcdc.txt                   | 82 +++++++++++++++++++
 2 files changed, 148 insertions(+)
 create mode 100644 doc/device-tree-bindings/video/tilcdc/panel.txt
 create mode 100644 doc/device-tree-bindings/video/tilcdc/tilcdc.txt

diff --git a/doc/device-tree-bindings/video/tilcdc/panel.txt b/doc/device-tree-bindings/video/tilcdc/panel.txt
new file mode 100644
index 0000000000..808216310e
--- /dev/null
+++ b/doc/device-tree-bindings/video/tilcdc/panel.txt
@@ -0,0 +1,66 @@
+Device-Tree bindings for tilcdc DRM generic panel output driver
+
+Required properties:
+ - compatible: value should be "ti,tilcdc,panel".
+ - panel-info: configuration info to configure LCDC correctly for the panel
+   - ac-bias: AC Bias Pin Frequency
+   - ac-bias-intrpt: AC Bias Pin Transitions per Interrupt
+   - dma-burst-sz: DMA burst size
+   - bpp: Bits per pixel
+   - fdd: FIFO DMA Request Delay
+   - sync-edge: Horizontal and Vertical Sync Edge: 0=rising 1=falling
+   - sync-ctrl: Horizontal and Vertical Sync: Control: 0=ignore
+   - raster-order: Raster Data Order Select: 1=Most-to-least 0=Least-to-most
+   - fifo-th: DMA FIFO threshold
+ - display-timings: typical videomode of lcd panel.  Multiple video modes
+   can be listed if the panel supports multiple timings, but the 'native-mode'
+   should be the preferred/default resolution.  Refer to
+   Documentation/devicetree/bindings/display/panel/display-timing.txt for display
+   timing binding details.
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+- enable-gpios: GPIO pin to enable or disable the panel
+
+Recommended properties:
+ - pinctrl-names, pinctrl-0: the pincontrol settings to configure
+   muxing properly for pins that connect to TFP410 device
+
+Example:
+
+	/* Settings for CDTech_S035Q01 / LCD3 cape: */
+	lcd3 {
+		compatible = "ti,tilcdc,panel";
+		pinctrl-names = "default";
+		pinctrl-0 = <&bone_lcd3_cape_lcd_pins>;
+		backlight = <&backlight>;
+		enable-gpios = <&gpio3 19 0>;
+
+		panel-info {
+			ac-bias           = <255>;
+			ac-bias-intrpt    = <0>;
+			dma-burst-sz      = <16>;
+			bpp               = <16>;
+			fdd               = <0x80>;
+			sync-edge         = <0>;
+			sync-ctrl         = <1>;
+			raster-order      = <0>;
+			fifo-th           = <0>;
+		};
+		display-timings {
+			native-mode = <&timing0>;
+			timing0: 320x240 {
+				hactive         = <320>;
+				vactive         = <240>;
+				hback-porch     = <21>;
+				hfront-porch    = <58>;
+				hsync-len       = <47>;
+				vback-porch     = <11>;
+				vfront-porch    = <23>;
+				vsync-len       = <2>;
+				clock-frequency = <8000000>;
+				hsync-active    = <0>;
+				vsync-active    = <0>;
+			};
+		};
+	};
diff --git a/doc/device-tree-bindings/video/tilcdc/tilcdc.txt b/doc/device-tree-bindings/video/tilcdc/tilcdc.txt
new file mode 100644
index 0000000000..7bf1bb4448
--- /dev/null
+++ b/doc/device-tree-bindings/video/tilcdc/tilcdc.txt
@@ -0,0 +1,82 @@
+Device-Tree bindings for tilcdc DRM driver
+
+Required properties:
+ - compatible: value should be one of the following:
+    - "ti,am33xx-tilcdc" for AM335x based boards
+    - "ti,da850-tilcdc" for DA850/AM18x/OMAP-L138 based boards
+ - interrupts: the interrupt number
+ - reg: base address and size of the LCDC device
+
+Recommended properties:
+ - ti,hwmods: Name of the hwmod associated to the LCDC
+
+Optional properties:
+ - max-bandwidth: The maximum pixels per second that the memory
+   interface / lcd controller combination can sustain
+ - max-width: The maximum horizontal pixel width supported by
+   the lcd controller.
+ - max-pixelclock: The maximum pixel clock that can be supported
+   by the lcd controller in KHz.
+ - blue-and-red-wiring: Recognized values "straight" or "crossed".
+   This property deals with the LCDC revision 2 (found on AM335x)
+   color errata [1].
+    - "straight" indicates normal wiring that supports RGB565,
+      BGR888, and XBGR8888 color formats.
+    - "crossed" indicates wiring that has blue and red wires
+      crossed. This setup supports BGR565, RGB888 and XRGB8888
+      formats.
+    - If the property is not present or its value is not recognized
+      the legacy mode is assumed. This configuration supports RGB565,
+      RGB888 and XRGB8888 formats. However, depending on wiring, the red
+      and blue colors are swapped in either 16 or 24-bit color modes.
+
+Optional nodes:
+
+ - port/ports: to describe a connection to an external encoder. The
+   binding follows Documentation/devicetree/bindings/graph.txt and
+   supports a single port with a single endpoint.
+
+ - See also Documentation/devicetree/bindings/display/tilcdc/panel.txt and
+   Documentation/devicetree/bindings/display/tilcdc/tfp410.txt for connecting
+   tfp410 DVI encoder or lcd panel to lcdc
+
+[1] There is an errata about AM335x color wiring. For 16-bit color mode
+    the wires work as they should (LCD_DATA[0:4] is for Blue[3:7]),
+    but for 24 bit color modes the wiring of blue and red components is
+    crossed and LCD_DATA[0:4] is for Red[3:7] and LCD_DATA[11:15] is
+    for Blue[3-7]. For more details see section 3.1.1 in AM335x
+    Silicon Errata:
+    http://www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=sprz360
+
+Example:
+
+	fb: fb at 4830e000 {
+		compatible = "ti,am33xx-tilcdc", "ti,da850-tilcdc";
+		reg = <0x4830e000 0x1000>;
+		interrupt-parent = <&intc>;
+		interrupts = <36>;
+		ti,hwmods = "lcdc";
+
+		blue-and-red-wiring = "crossed";
+
+		port {
+			lcdc_0: endpoint at 0 {
+				remote-endpoint = <&hdmi_0>;
+			};
+		};
+	};
+
+	tda19988: tda19988 {
+		compatible = "nxp,tda998x";
+		reg = <0x70>;
+
+		pinctrl-names = "default", "off";
+		pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
+		pinctrl-1 = <&nxp_hdmi_bonelt_off_pins>;
+
+		port {
+			hdmi_0: endpoint at 0 {
+				remote-endpoint = <&lcdc_0>;
+			};
+		};
+	};
-- 
2.17.1



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